Talk:Factor analysis

Independence v.s. Orthogonality

In section "Mathematical model of the same example" the text says:

The errors are assumed to be independent of the factors:

$$\sum _i{F}_{pi}{\epsilon }_{ai}=0$$

I don't understand how this is an assumption. The equation seems as if factors and errors were orthogonal by construction. As an assumption I would have expected an expected value on the left hand side. Matze-pigon (talk) 18:39, 27 February 2023 (UTC)